1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device which includes a semiconductor substrate having a semiconductor circuit on a principal plane thereof, with through holes extending through the semiconductor substrate from the principal plane toward a rear surface thereof, and penetration electrodes formed in the through holes with their one ends protruded from the rear surface of the semiconductor substrate.
2. Description of the Related Art
In the past, a known semiconductor device with penetration electrodes has been manufactured in the following procedure.
First, recesses are formed in a substrate main body or substrate proper having a semiconductor circuit on one surface thereof, and then insulation films are formed on inner wall surfaces of the recesses. Thereafter, a conductive material is embedded into the recesses through the insulation films to form embedded electrodes which later constitute penetration electrodes.
Subsequently, the rear surface of the substrate proper is ground up to the bottom of each recess, i.e., until one end faces of the embedded electrodes are exposed from the rear surface, thereby forming the penetration electrodes. Then, the rear surface of the substrate proper is removed by means of etching so that the penetration electrodes are protruded from the rear surface of the substrate proper to form a thinned semiconductor substrate. Thereafter, an insulation film is deposited on the entire rear surface of the semiconductor substrate and the one end faces of the penetration electrodes.
Finally, the insulation film covering the end faces of the penetration electrodes is removed (for instance, see a first patent document: Japanese patent laid-open No. 2001-53218).
The above-mentioned method for manufacturing a semiconductor device involves the following problem. That is, it is necessary to protrude the one end portions of the penetration electrodes from the rear surface of the substrate proper by etching the substrate proper made of silicon. Therefore, in the case of using dry etching to this end, it is difficult to uniformly etch the rear surface of the substrate proper since contamination of the substrate proper due to grinding thereof in a preceding process step or the like would greatly influence the surface condition of the substrate proper. As a result, a special process is required for removing such contamination.
On the other hand, in the case of using wet etching, there arises another problem in that when the rear surface of the substrate proper made of silicon is continuously etched, it is difficult to exactly stop the etching at a prescribed amount of etching. Accordingly, it is difficult to control the amounts of protrusion of the penetration electrodes from the rear surface of the substrate proper in a precise manner.
In addition, after an insulation film is deposited on the entire rear surface of the semiconductor substrate and the end faces of the penetration electrodes, a process step of finally removing those portions of the insulation film which cover the end faces of the penetration electrodes is separately needed, and hence the semiconductor device manufacturing procedure as a whole is accordingly complicated.
The present invention is intended to obviate the various problems as referred to above, and has for its object to provide a method for manufacturing a semiconductor device in which it is easy to control the amounts of protrusion of penetration electrodes from a rear surface of a substrate proper in a precise manner.
According to one aspect, the present invention resides in a method for manufacturing a semiconductor device which includes a semiconductor substrate having a semiconductor circuit on a principal plane thereof, with through holes extending through the semiconductor substrate from the principal plane toward a rear surface thereof, and penetration electrodes formed in the through holes with their one ends protruded from the rear surface of the semiconductor substrate. The method includes: a recess forming step of forming recesses in a substrate proper that has the semiconductor circuit formed on one surface thereof; an insulation film forming step of forming an insulation film on an inner wall surface of each of the recesses; an embedded electrode forming step of filling a conductive material into the recesses through the insulation films to form embedded electrodes that constitute the penetration electrodes; a penetration electrode forming step of forming the penetration electrodes by removing a rear side of the substrate proper opposite to the one surface thereof until one end face of each of the embedded electrodes is exposed; an anodic oxide film forming step of anodizing the rear surface of the substrate proper to form an anodic oxide film; and a semiconductor substrate forming step of forming the semiconductor substrate by removing the anodic oxide film (9) by means of etching.
According to another aspect, the present invention resides in a method for manufacturing a semiconductor device which includes a semiconductor substrate having a semiconductor circuit on a principal plane thereof, with through holes extending through the semiconductor substrate from the principal plane toward a rear surface thereof, and penetration electrodes formed in the through holes with their one ends protruded from the rear surface of the semiconductor substrate. The method includes: a recess forming step of forming recesses in a substrate proper that has the semiconductor circuit formed on one surface thereof; an insulation film forming step of forming an insulation film on an inner wall surface of each of the recesses; an embedded electrode forming step of filling a conductive material into the recesses through the insulation films to form embedded electrodes that constitute the penetration electrodes; a removal step of removing a rear side of the substrate proper opposite to the one surface thereof until one end face of each of the embedded electrodes is exposed; an anodic oxide film forming step of anodizing the rear surface of the substrate proper to form an anodic oxide film; a semiconductor substrate forming step of removing the anodic oxide film by means of etching to form the penetration electrodes and the thinned semiconductor substrate; and a removal step of removing the insulation films which cover one end portions of the penetration electrodes.